Multi-user interactive display system

CROSS-REFERENCE TO RELATED APPLICATIONS

p-0002Reference is made to commonly-assigned, co-pending U.S. patent application Ser. No. 13/364,409, entitled: “Method for controlling interactive display system”, by Ptucha et al.; and to co-pending U.S. patent application Ser. No. 13/364,417, entitled: “Interactive digital advertising system”, by Ptucha et al., each of which is incorporated herein by reference.

FIELD OF THE INVENTION

p-0003This invention pertains to the field of digital imaging systems and more particularly to a method for interactively controlling content displayed on a soft copy display.

BACKGROUND OF THE INVENTION

p-0004There has been much research on improving the overall experience of human-computer interaction. Multi-modal affective computing, or the automatic extraction of human emotion using multiple input modalities, is a field that is revolutionizing human computer interfaces (for example, see Afzal et al., “Intentional affect: an alternative notion of affective interaction with a machine,” Proc. 23rd British HCI Group Annual Conference on People and Computers: Celebrating People and Technology, pp. 370-374, 2009). In an article entitled “Human-computer intelligent interaction: A survey” (4th IEEE International Workshop on Human-Computer Interaction, pp. 1-5, 2007), Lew et al. argue that in order to achieve effective human-to-computer communication, as the human interacts with the computer, the computer also needs to interact with the human. The goal of human-computer interaction is twofold: to have the computer engage and embrace all the human subtleties, that as a whole, convey the true underlying message; and to interact with the human in his/her natural setting, eliminating ambiguous or awkward input modalities.

p-0005Computers are becoming ubiquitous and are increasingly diffusing into our environment, moving from primarily foreground devices requiring purposeful user interactions (e.g., using a mouse or a keyboard) to invisible background devices. Next generation computing devices will need to increasingly interact with humans in a way that is very similar to human-to-human communication.

p-0006With the introduction of low-cost depth cameras, such as those associated with the Kinect game console available for the Xbox 360 gaming system from Microsoft Corporation of Redmond, Wash., depth estimation has become a viable option for widespread use. Depth information provides much more salient information than RGB or grayscale cameras for subject gesture recognition. The extraction of objects against complex backgrounds, and the tracking of these objects has been reduced from a highly compute-intensive, error-prone task to one that is much more robust and works with much simpler methods, spurring a revolutionary leap in machine understanding (see Shotton, et al., “Real-time human pose recognition in parts from single depth images,” Computer Vision and Pattern Recognition, pp. 1297-1304, 2011).

p-0007Gesture recognition using depth cameras is now able to recognize an increasingly sophisticated dictionary of commands. Examples of gesture recognition methods are described by Suma et al. in the article “FAAST: The Flexible Action and Articulated Skeleton Toolkit” (Proc. IEEE Virtual Reality Conference, pp. 247-248, 2011; and by Kaplan in the article “Are gesture-based interfaces the future of human computer interaction?” (Proc. International Conference on Multimodal Interfaces, pp. 239-240, 2009). The rapid development of numerous gesture control platforms has resulted in a plethora of application-specific, gesture-based commands. These commands have been driven by the gaming and home entertainment markets, which generally have one or two users in constrained settings.

p-0008U.S. Patent Application Publication No. 2009/0077504 to Bell et al., entitled “Processing of gesture-based user interactions,” discloses methods for extracting hand gestures for interactive displays, as well as inclusion of visible indicators on a screen, much like a mouse fiducial is used in modern day computers.

p-0009U.S. Patent Application Publication 2011/0157009 to Kim et al., entitled “Display device and control method thereof,” discloses a method for using human gestures to control a device. The method is based upon human silhouette or skeletal joint estimation of the human operator.

p-0010U.S. Patent Application Publication 2011/0197263 to Stinson, entitled “Systems and methods for providing a spatial-input-based multi-user shared display experience,” discloses a method for allowing multiple human users to control a device using gesture control. The method primarily uses hand gestures for living room TV control allowing split screen and multi-window displays, whereby each user controls each window.

p-0011U.S. Pat. No. 5,563,988 to Maes et al., entitled “Method and system for facilitating wireless, full-body, real-time user interaction with a digitally represented visual environment,” discloses a method for allowing a human user to insert oneself into a virtual reality environment. The method allows for interaction with the environment and objects within it, including the extraction of information.

p-0012As interactive devices become more ubiquitous, gesture commands which are instinctive and intuitive for humans to perform in unconstrained settings will need to be introduced. Additionally, intuitive ways for the computer to communicate back to the user will also be needed.

SUMMARY OF THE INVENTION

p-0013The present invention represents a multi-user interactive display system, comprising:

p-0014a soft-copy display including at least an information display region and a command control region;

p-0015a digital image capture system positioned to capture a time sequence images of users located in a field-of-view of the soft-copy display;

p-0016a data processing system; and

p-0017a program memory communicatively connected to the data processing system and storing instructions configured to cause the data processing system to implement a method for interactively controlling content displayed in the information display region, wherein the method includes: <ul><li id="ul0001-0001" num="0000"><ul><li id="ul0002-0001" num="0017">analyzing a time sequence of images captured by the digital image capture system to detect a plurality of users in the field-of-view of the soft-copy display who are viewing the soft copy display;</li><li id="ul0002-0002" num="0018">designating at least one of the detected plurality of users to be a controlling user;</li><li id="ul0002-0003" num="0019">displaying the captured time sequence of images in the command control region, wherein the detected users are demarked using graphical elements, and wherein the graphical element associated with the at least one controlling user is differentiated from the graphical elements associated with the other detected users to provide an indication of which of the plurality of users is the controlling user; and</li><li id="ul0002-0004" num="0020">analyzing the captured time sequence of images to detect a gesture made by the controlling user and updating content displayed in the information display region accordingly.</li></ul></li></ul>

p-0018This invention has the advantage that the interactive display system is enabled to communicate information to the users regarding which user is the controlling user who is controlling the device at any point in time. Optionally, information about a priority order of the other detected users can also be provided.

p-0019It has the additional advantage that the controlling user can control the interactive display system using to a plurality of predefined gestures. The predefined gestures can include relinquish control gesture enabling the controlling user to relinquish control to another user, and a control request gesture that enables a non-controlling user request that they be moved to a higher position in the priority queue.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0020<figref idrefs="DRAWINGS">FIG. 1</figref> is a high-level diagram showing the components of a system for gesture-based human computer interaction according to an embodiment of the present invention;

p-0021<figref idrefs="DRAWINGS">FIG. 2</figref> is diagram showing the components of a multi-user interactive display system according to an embodiment of the present invention;

p-0022<figref idrefs="DRAWINGS">FIG. 3</figref> is a flowchart of a method for controlling an interactive display system using gestures in accordance with the present invention;

p-0023<figref idrefs="DRAWINGS">FIG. 4</figref> shows an example of a depth image captured using a depth camera;

p-0024<figref idrefs="DRAWINGS">FIG. 5</figref> illustrates examples of gestures that can be used to control the interactive display system; and

p-0025<figref idrefs="DRAWINGS">FIG. 6</figref> shows an example of a digital display showing content for a digital signage application.

p-0026It is to be understood that the attached drawings are for purposes of illustrating the concepts of the invention and may not be to scale.

DETAILED DESCRIPTION OF THE INVENTION

p-0027In the following description, some embodiments of the present invention will be described in terms that would ordinarily be implemented as software programs. Those skilled in the art will readily recognize that the equivalent of such software may also be constructed in hardware. Because image manipulation algorithms and systems are well known, the present description will be directed in particular to algorithms and systems forming part of, or cooperating more directly with, the method in accordance with the present invention. Other aspects of such algorithms and systems, together with hardware and software for producing and otherwise processing the image signals involved therewith, not specifically shown or described herein may be selected from such systems, algorithms, components, and elements known in the art. Given the system as described according to the invention in the following, software not specifically shown, suggested, or described herein that is useful for implementation of the invention is conventional and within the ordinary skill in such arts.

p-0028The invention is inclusive of combinations of the embodiments described herein. References to “a particular embodiment” and the like refer to features that are present in at least one embodiment of the invention. Separate references to “an embodiment” or “particular embodiments” or the like do not necessarily refer to the same embodiment or embodiments; however, such embodiments are not mutually exclusive, unless so indicated or as are readily apparent to one of skill in the art. The use of singular or plural in referring to the “method” or “methods” and the like is not limiting. It should be noted that, unless otherwise explicitly noted or required by context, the word “or” is used in this disclosure in a non-exclusive sense.

p-0029<figref idrefs="DRAWINGS">FIG. 1</figref> is a high-level diagram showing the components of a system for gesture-based human computer interaction according to an embodiment of the present invention. The system includes a data processing system <b>110</b>, a peripheral system <b>120</b>, a user interface system <b>130</b>, and a data storage system <b>140</b>. The peripheral system <b>120</b>, the user interface system <b>130</b> and the data storage system <b>140</b> are communicatively connected to the data processing system <b>110</b>.

p-0030The data processing system <b>110</b> includes one or more data processing devices that implement the processes of the various embodiments of the present invention, including the example processes described herein. The phrases “data processing device” or “data processor” are intended to include any data processing device, such as a central processing unit (“CPU”), a desktop computer, a laptop computer, a mainframe computer, a personal digital assistant, a Blackberry™, a digital camera, cellular phone, or any other device for processing data, managing data, or handling data, whether implemented with electrical, magnetic, optical, biological components, or otherwise.

p-0031The data storage system <b>140</b> includes one or more processor-accessible memories configured to store information, including program memory storing instructions for causing the data processing system <b>110</b> to execute the processes of the various embodiments of the present invention, including the example processes described herein. The data storage system <b>140</b> may be a distributed processor-accessible memory system including multiple processor-accessible memories communicatively connected to the data processing system <b>110</b> via a plurality of computers or devices. On the other hand, the data storage system <b>140</b> need not be a distributed processor-accessible memory system and, consequently, may include one or more processor-accessible memories located within a single data processor or device.

p-0032The phrase “processor-accessible memory” is intended to include any processor-accessible data storage device, whether volatile or nonvolatile, electronic, magnetic, optical, or otherwise, including but not limited to, registers, floppy disks, hard disks, Compact Discs, DVDs, flash memories, ROMs, and RAMs.

p-0033The phrase “communicatively connected” is intended to include any type of connection, whether wired or wireless, between devices, data processors, or programs in which data may be communicated. The phrase “communicatively connected” is intended to include a connection between devices or programs within a single data processor, a connection between devices or programs located in different data processors, and a connection between devices not located in data processors at all. In this regard, although the data storage system <b>140</b> is shown separately from the data processing system <b>110</b>, one skilled in the art will appreciate that the data storage system <b>140</b> may be stored completely or partially within the data processing system <b>110</b>. Further in this regard, although the peripheral system <b>120</b> and the user interface system <b>130</b> are shown separately from the data processing system <b>110</b>, one skilled in the art will appreciate that one or both of such systems may be stored completely or partially within the data processing system <b>110</b>.

p-0034The peripheral system <b>120</b> may include one or more devices configured to provide digital content records to the data processing system <b>110</b>. For example, the peripheral system <b>120</b> may include digital still cameras, digital video cameras, cellular phones, or other data processors. The data processing system <b>110</b>, upon receipt of digital content records from a device in the peripheral system <b>120</b>, may store such digital content records in the data storage system <b>140</b>.

p-0035The user interface system <b>130</b> may include a mouse, a keyboard, another computer, or any device or combination of devices from which data is input to the data processing system <b>110</b>. In this regard, although the peripheral system <b>120</b> is shown separately from the user interface system <b>130</b>, the peripheral system <b>120</b> may be included as part of the user interface system <b>130</b>.

p-0036The user interface system <b>130</b> also may include a display device, a processor-accessible memory, or any device or combination of devices to which data is output by the data processing system <b>110</b>. In this regard, if the user interface system <b>130</b> includes a processor-accessible memory, such memory may be part of the data storage system <b>140</b> even though the user interface system <b>130</b> and the data storage system <b>140</b> are shown separately in <figref idrefs="DRAWINGS">FIG. 1</figref>.

p-0037The present invention will now be described with reference to <figref idrefs="DRAWINGS">FIGS. 2 and 3</figref>. <figref idrefs="DRAWINGS">FIG. 2</figref> shows an example of an interactive display system <b>200</b> according to an embodiment of the present invention in which users <b>231</b> and <b>232</b> interact and control the content of a soft-copy digital display <b>205</b> using body gestures, facial gestures, and head pose. In some embodiments, the content displayed on the digital display <b>205</b> can also be automatically changed based upon the number of users or associated attributes of the users, where attributes can include, for example, distance from display, gender, weight, height, hair color, hair style, facial hair type, complexion type, eye glasses type, clothing type and jewelry type. The interactive display system <b>200</b> includes at least one digital camera <b>210</b> having a corresponding field of view <b>220</b>. The digital display <b>205</b> includes an information display region <b>245</b> where various types of information can be displayed, such as text, graphics or images (still or video), as well as a command control region <b>240</b>.

p-0038In a preferred embodiment, a live video display showing a time sequence of images <b>250</b> captured by the digital camera <b>210</b> of the field of view <b>220</b> is displayed in the command control region <b>240</b> that occupies a portion of the digital display <b>205</b>. The image <b>250</b> includes representations of users <b>231</b> and <b>232</b> (user images <b>251</b> and <b>252</b>) when the users <b>231</b> and <b>232</b> are within the field of view <b>220</b> of the digital camera <b>210</b>.

p-0039In a preferred embodiment, the image <b>250</b> is mirrored left-right relative to the captured video so that the left-right orientation of the users <b>231</b> and <b>232</b> is the same as the left-right orientation of the user images <b>251</b> and <b>252</b> (i.e., the left-most user <b>231</b> is shown as the left-most user image <b>251</b>). It has been found that this generally provides a more intuitive user experience. In other embodiments, the left-right mirroring step may be omitted.

p-0040In a preferred embodiment the users <b>231</b> and <b>232</b> use gestures to control a visible fiducial <b>260</b> provided on the digital display <b>205</b>, much like a user can use a mouse to control a cursor on a computer display. As will be discussed in more detail later, one of the users <b>231</b> and <b>232</b> is generally designated to be a controlling user. Graphical elements are preferably included on the image <b>250</b> displayed in the command control region <b>240</b>. Various attributes of the graphical elements can be used to indicate which of the users <b>231</b> and <b>232</b> is the controlling user. In the example of <figref idrefs="DRAWINGS">FIG. 2</figref>, user <b>231</b> is the controlling user as reflected by the controlling user graphical element <b>261</b>. The user <b>232</b> is designated to be a secondary user as reflected by the secondary user graphical element <b>262</b>. In this example, the controlling user graphical element <b>261</b> is a square bounding box having a bold solid outline enclosing the face of the controlling user <b>231</b>, and the secondary user graphical element <b>262</b> is a square bounding box having a finer dashed outline. In some embodiments the controlling user can be indicated using adjusting other attributes of the graphical elements such as color or transparency.

p-0041In other embodiments, the graphical elements can use other types of geometrical shapes to enclose the face of the user, or can take other forms such as avatars. For example, avatars can be placed in proximity to the detected users, or avatar heads can be overlaid on the heads of the detected users. The avatars can be photographic images of real people (e.g., models or celebrities), animals or objects, or can be graphical representations of people (e.g., caricatures), animals (e.g., cartoon characters) or objects (e.g., icons). In some embodiments, avatars can be provided having a relationship to the venue where the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) is used. For example, if the interactive display system <b>200</b> is used in a theme park, then avatars corresponding to cartoon characters associated with the theme park can be used.

p-0042In some embodiments, attributes of the avatars can be adjusted according to attributes of the detected users. Example of attributes of the detected users would include facial expression, facial orientation, visual focus of attention, age, gender, race, hair color, hair style, facial hair, complexion height, weight, eye glasses, clothing or jewelry. Another attribute of the detected users that can be sensed is the presence of an identifying object such as an ID card, a name badge, a wireless ID tag or a uniform type/marking. In some implementations, one or more attributes of the avatars can be adjusted to match corresponding attributes of the detected users. For example, the gender, race and hair color of the avatar can be chosen to match the detected user, or the facial expression of avatar can be adjusted to reflect the facial expression of the detected user.

p-0043When there are more than two users, attributes of the corresponding graphical elements can optionally be used to reflect a priority ordering of the users to communicate a relative position of the users in a priority queue. The priority queue indicates an order that the users will be considered to be selected as the next controlling user. In some embodiments, variations in the color, shape, size or transparency of the graphical elements can be used to provide an indication of the user's relative position in the priority queue. For example, the controlling user can be indicated using a green outline, and the rest of the users can be indicated using outlines that vary from yellow for the next user in the priority queue to red for the last user in the priority queue. In some embodiments, the graphical elements can include numerical values that provide the indication of the relative position of the users within the priority queue. For example, a “1” can be included in the graphical element for the first user in the priority queue, a “2” can be included in the graphical element for the second user in the priority queue, and so forth.

p-0044In some embodiments, more than one controlling user can be designated, where each of the controlling users can be controlling different aspects of the information displayed in the information display region <b>245</b>. In such cases, it is generally desirable that some aspect of the graphical elements provide an indication of which aspects each controlling user is controlling. For example, the color of the fiducial <b>260</b> can match the color of the controlling user graphical element <b>261</b> for the corresponding controlling user. Alternately the association between the fiducial <b>260</b> and the controlling user graphical element <b>261</b> can be reflected using some other attribute such as shape, size or pattern. For example, an avatar can be associated with each of the controlling users, and the avatar can be used for both the controlling user graphical element <b>261</b> and the corresponding fiducial <b>260</b>.

p-0045<figref idrefs="DRAWINGS">FIG. 3</figref> shows a flowchart of a method for controlling the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) in accordance with the present invention. A display image in command control region step <b>310</b> continuously displays images from a video feed (i.e., a time sequence of images) captured by the digital camera <b>210</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) to the command control region <b>240</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>).

p-0046A user detection/tracking step <b>320</b> is used to detect users in the images captured by the digital camera <b>210</b>. In a preferred embodiment, the user detection/tracking step <b>320</b> detects the users by performing face detection on the current captured image. In some embodiments, the interactive display system <b>200</b> can include an optional “depth camera” (not shown in <figref idrefs="DRAWINGS">FIG. 2</figref>) that can be used to determine a depth map of distances between the camera and objects in the scene. In this case, the user detection/tracking step <b>320</b> can detect users by analyzing image data captured by the depth camera to detect the presence of human silhouettes. The user detection/tracking step <b>320</b> can optionally combine the results of multiple user detection methods (e.g., face detection and depth map analysis) to provide more accurate detection results. In some embodiments, the user detection/tracking step <b>320</b> can track detected users from one frame of the captured time sequence of images to the next frame. This can increase the reliability and speed of the user detection process.

p-0047A users found test <b>330</b> is used to evaluate the results of the user detection/tracking step <b>320</b> to determine whether any users were detected in the captured images. If no users were detected, the system returns to the display images in command control region step <b>310</b>. If users were detected, the interactive display system <b>200</b> initiates a human-to-computer interaction process.

p-0048A determine controlling user(s) step <b>340</b> evaluates the detected users and designates at least one user to be a controlling user. In a preferred embodiment, the determine controlling user(s) step <b>340</b> determines a priority order for each of the detected users in the field of view <b>220</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) of the digital camera <b>210</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) and keeps track of the priority order in a priority queue. The highest priority user is then designated to be a controlling user. The priority order (and therefore the relative position in the priority queue) indicates an order that the users will be considered to be selected as the controlling user. In some embodiments, more than one of the highest priority users can be designated to be a controlling user to allow for multiple users to interact simultaneously with the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>).

p-0049The determine controlling user(s) step <b>340</b> can determine the priority order for the users in various ways. In a preferred embodiment, the priority order is determined responsive to a distance of the user from the digital display <b>205</b> and a duration of time that the user has been viewing the digital display <b>205</b>. For example, a priority value P_ican be determined for the i^thuser (where iε1 . . . N, and N is the number of detected users) by performing a weighted sum involving the distance d_iof the user from the digital display <b>205</b> and the time t_ithat the user has been viewing the digital display <b>205</b>:

p-0050<maths id="MATH-US-00001" num="00001"><math overflow="scroll"><mtable><mtr><mtd><mtable><mtr><mtd><mrow><msub><mi>P</mi><mi>i</mi></msub><mo>=</mo><mi /><mo>⁢</mo><mrow><mrow><msub><mi>W</mi><mi>D</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mrow><mn>1</mn><mo>-</mo><mfrac><msub><mi>d</mi><mi>i</mi></msub><msub><mi>d</mi><mi>m</mi></msub></mfrac></mrow><mo>)</mo></mrow></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>T</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mfrac><msub><mi>t</mi><mi>i</mi></msub><msub><mi>t</mi><mi>m</mi></msub></mfrac><mo>)</mo></mrow></mrow></mrow></mrow></mtd></mtr><mtr><mtd><mrow><mo>=</mo><mi /><mo>⁢</mo><mrow><mrow><msub><mi>W</mi><mi>D</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mrow><mn>1</mn><mo>-</mo><msub><mi>D</mi><mi>i</mi></msub></mrow><mo>)</mo></mrow></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>T</mi></msub><mo>⁢</mo><msub><mi>T</mi><mi>i</mi></msub></mrow></mrow></mrow></mtd></mtr></mtable></mtd><mtd><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mtd></mtr></mtable></math></maths><br /> where W_Dand W_Tare weighting constants, d_m=max(d_i) and t_m=max(t_i) are the maximum distance and time across all of the currently detected users, respectively, and D_i=d_i/d_mand T_i=t_i/t_m, are normalized distances and times, respectively. The values of the normalized distances and times will be in the range from 0 to 1, thereby effectively normalizes the priority values so that they will have similar magnitudes independent of the arrangement of the users. The priority values determined using Eq. (1) will be larger for users that have been standing in front of the display for longer times relative to users that just arrived, and for users that are standing closer relative to those that are further away. As users come and go, the priority values adjust themselves in a natural fashion, strikingly similar to what a group of humans would do if they were waiting for a chance to talk to a single person.

p-0051In some embodiments, the distance d_iis determined by using a depth camera as described earlier. In other embodiments, the distance d_ican be estimated by determining the size of the user's head and assuming that the size of the head will be inversely related to the distance between the user and the digital display <b>205</b>. The time t_ican be determined by tracking the user from frame-to-frame in the time sequence of images and keeping track of how many frames that the user has been in the field of view <b>220</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). Once the priority values P_iare determined for each user, they can be sorted to determine the priority order of the users.

p-0052Generally the user having the highest priority value P_i(and therefore the highest priority in the priority order) is designated to be the controlling user. However, to avoid frequent changes in the identity of the controlling user due to small changes in the relative position of the users, it can be desirable to give higher priority to the user who is currently designated to be the controlling user. One mechanism for providing this functionality is to incorporate an additional term into the computation of the priority value that provides additional weight for any users that are currently designated to be controlling users:

p-0053<maths id="MATH-US-00002" num="00002"><math overflow="scroll"><mtable><mtr><mtd><mrow><msub><mi>P</mi><mi>i</mi></msub><mo>=</mo><mrow><mrow><msub><mi>W</mi><mi>D</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mrow><mn>1</mn><mo>-</mo><mfrac><msub><mi>D</mi><mi>i</mi></msub><msub><mi>D</mi><mi>m</mi></msub></mfrac></mrow><mo>)</mo></mrow></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>T</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mfrac><msub><mi>T</mi><mi>i</mi></msub><msub><mi>T</mi><mi>m</mi></msub></mfrac><mo>)</mo></mrow></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>C</mi></msub><mo>⁢</mo><msub><mi>C</mi><mi>i</mi></msub></mrow></mrow></mrow></mtd><mtd><mrow><mo>(</mo><mn>2</mn><mo>)</mo></mrow></mtd></mtr></mtable></math></maths><br /> where C_iis a Boolean value which is “1” for users who are currently designated to be controlling users and “0” for users who are currently designated to be non-controlling users, and W_Cis a weighting constant.

p-0054An update command control region step <b>350</b> updates the information displayed in the command control region <b>240</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) to provide a visual indication of the identity of the controlling user(s) and the position of each of the detected users in the priority queue. As was discussed with reference to <figref idrefs="DRAWINGS">FIG. 2</figref>, in some embodiments this feature is provided by controlling one or more attributes (e.g., color) of graphical elements (e.g. bounding boxes enclosing the faces of the users) that are displayed for each user. In this way, it is readily apparent to all users who is in control and what is the position of each user within the priority queue.

p-0055After the controlling user(s) are designated, a detect controlling user gesture step <b>360</b> analyzes the time sequence of captured images to detect any gestures made be the controlling user(s) corresponding to one of a predefined set of standardized gestures. The detection of the gestures enable the controlling users to interact with the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>), much like a user can interact with a conventional computer using input devices such as a mouse. The detected gestures can include a combination of body gestures, facial expression gestures, and facial pose gestures. Examples of types of gestures would include a pointing gesture that enables a user to control a pointing location on the digital display <b>205</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>), a selection gesture that enables selection of a selectable active user interface element on the digital display <b>205</b>, a movement gesture that enables movement of items on the digital display <b>205</b>, a relinquish control gesture that enables the controlling user to relinquish control to the next user in the priority queue, and a control request gesture that enables a non-controlling user to request that he/she be moved to a higher position in the priority queue.

p-0056For example, in an interactive window shopping display system application, a controlling user may use a pointing gesture to point to a pair of jeans shown in the information display region <b>245</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) of the digital display <b>205</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). The controlling user can then use a selection gesture to select the pair of jeans, thereby causing the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) to display information about the pair of jeans (e.g., price, store inventory, or designer) in the information display region <b>245</b>. As an alternate example in an interactive airport display system application, a controlling user may select content displayed in the information display region <b>245</b> to request more information on an airline, flight, destination site, or weather conditions.

p-0057A gesture detected test <b>370</b> is used to determine whether the detect controlling user gesture step <b>360</b> detected a gesture. If no gesture was detected, the process returns back to the display images in command control region step <b>310</b> to continue the process of monitoring the sequence of captured images to detect gestures made by controlling users.

p-0058In response to detecting a gesture made by the controlling user in the detect controlling user gesture step <b>360</b>, the information display region <b>245</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) is updated accordingly using an update information display region step <b>380</b>. For example, the information display region <b>245</b> can include a selectable active element (e.g., a “buttons” or a “link”) having an associated predefined action (e.g., to display information about a selected product). If the user performs a pointing action to point to the selectable active element and a selecting gesture to select the selectable active element, the predefined action is initiated and the information display region <b>245</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) is updated accordingly (e.g., by displaying the information about the selected product). Optionally, an update command control region step <b>390</b> can also be used to update the content displayed in the command control region <b>240</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). For example, a text message may be displayed to provide visual feedback indicating what command is being executed.

p-0059After performing any appropriate actions in response to any detected gesture made by the controlling user, the process returns back to the display images in command control region step <b>310</b> to continue the process of monitoring the sequence of captured images to detect any additional gestures made by controlling users.

p-0060Various aspects of the process shown in <figref idrefs="DRAWINGS">FIG. 3</figref> will now be discussed in more detail. In accordance with some embodiments of the present invention, the user detection/tracking step <b>320</b> determines the size and location of each face in the images in the captured video sequence. This can be accomplished using any method known in the art, such as that described by Viola et al. in the article “Rapid object detection using a boosted cascade of simple features” (Computer Vision and Pattern Recognition, Vol. 1, pp. 1-511-1-518, 2001), which is incorporated herein by reference. This approach utilizes a training set of positive face and negative non-face images. Simple Haar-like wavelet weak classifier features are computed for the positive and negative training images. While no single Haar-like feature is sufficient to classify a region as face or non-face, groupings of many features form a strong classifier that can be used to determine whether or not a test region is a face. Windows of different sizes are slid across the image in order to detect faces at different locations and sizes. Because this detection process can be quite compute intensive, optimizations such as an integral image and cascades of weak classifiers can be used to make the algorithm work faster. These algorithms have been further optimized such that they can find all faces of varying pose in real time. In other embodiments, faces in an image can be detected using the method described by Schneiderman in the article “Feature-centric evaluation for efficient cascaded object detection” (Computer Vision and Pattern Recognition, Vol. 2, pp. II-29-II-36, 2004).

p-0061Once a face is found, neural networks, support vector machines, or similar classifying means can be trained to locate specific features such as the eyes, nose, and mouth. Related features such as the corners of eyes, eye brows, chin, and edge of cheeks can then be found using geometric rules based upon anthropometric constraints, such as those described by DeMenthon et al. in the article “Model Based Pose in 25 Lines of Code” (International Journal of Computer Vision, Vol. 15, pp. 123-141, 1995), which is incorporated herein by reference.

p-0062Active shape models as described by Cootes et al. in the article “Active shape models—their training and application” (Computer Vision and Image Understanding, vol. 61, pp. 38-59, 1995), which is incorporated herein by reference, can be used to identify facial features such as eyes, nose, lips, face outline, and eyebrows. The identified facial features can be analyzed to determine various attributes associated with the user, such as facial size, race, hair color, hair style, facial hair type (e.g., full beard, goatee, mustache or none), eye glasses attributes, clothing attributes, height attributes, weight attributes, complexion attributes, jewelry attributes, makeup attributes, and whether the user's eyes and mouth are open. The identified facial attributes can also be analyzed to infer other types of information associated with the user such as the user's age, gender, height, weight, facial expression (e.g., happy, sad, scared, serious, or neutral), facial orientation, visual focus of attention. In some embodiments, facial recognition algorithms can be used to analyze the facial features to determine the user's identity.

p-0063Facial pose attributes for the detected faces can be determined from extracted facial features using any method known in the art. For example, Ptucha et al., in an article entitled “Facial Pose Estimation Using a Symmetrical Feature Model”, Proc. IEEE International Conference on Multimedia and Expo, pp. 1664-1667, 2009), which is incorporated herein by reference, describe a method for determining a facial pose using a geometric model that adheres to anthropometric constraints.

p-0064The determined user attributes can be used in a variety of ways. For example, as discussed earlier the user attributes can be used to adjust attributes of avatars associated with the users.

p-0065In some embodiments, the content displayed in the information display region <b>245</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) can be adjusted responsive to the determined user attributes. For example, if the controlling user is a female estimated to be in her twenties, advertising for clothing products can be displayed which would be likely to be of interest to a person fitting that demographic. Demographic information that is considered can include any attribute of the user including an age attribute, a gender attribute, a race attribute, a hair color attribute, a facial hair attribute, an eye glasses attribute, a clothing attribute, a complexion attribute, a jewelry attribute, a height attribute or a weight attribute.

p-0066In some embodiments, the determined user attributes can be used by the determine controlling user(s) step <b>340</b> during the determination of the priority order for the detected users. For example, a facial size attribute can be used to estimate the distance of the user from the digital display <b>205</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). Higher priority can be assigned to users that are closer to the digital display <b>205</b> than to users that are farther away. Similarly, facial orientation or visual focus of attention attributes can be evaluated to assign a higher priority to users that are looking directly at the digital display <b>205</b>. In some embodiments where a facial recognition process is used, higher priority can be assigned to recognized users than to unknown users.

p-0067As mentioned earlier, in some embodiments the user detection/tracking step <b>320</b> can use depth information during the process of detecting and tracing the users. The use of depth sensors, such as the depth camera associated with Microsoft's Kinect game console, enables multiple deformable objects to be robustly tracked regardless of pose. For example, <figref idrefs="DRAWINGS">FIG. 4</figref> shows the depth image <b>400</b> captured by a depth camera showing two users <b>410</b> and <b>411</b> interacting with an interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). The pixel values in the depth image <b>400</b> provide an estimate of the depth (i.e., the distance from the digital display <b>205</b> to the scene, where lighter pixels correspond to objects that are closer and darker pixels correspond to objects that are farther away. In a preferred embodiment, only moving objects are considered to be candidate users. Objects that are moving against the static background can be extracted from the depth image <b>400</b> using conventional computer vision algorithms such as temporal thresholding. Initially, any contiguous moving object is considered as a candidate user. In addition to valid users, the moving objects could also include other types of objects such as cats, dogs or moving cars. The detected moving objects are passed on to a human skeletonization estimator to determine whether the object is a human. If the object is determined to be a human, it is tracked until it leaves the field of view <b>220</b> of the digital camera <b>210</b>, otherwise it is ignored.

p-0068An example of a human skeletonization estimator that can be used in accordance with the present invention is described in the aforementioned article “Real-Time Human Pose Recognition in Parts from Single Depth Images,” by J. Shotton, et al. According to this method, each section of the silhouette of an object is analyzed to determine whether it corresponds to a human body part, where kinematic and temporal constraints ensure plausible limb identification. The first step is to assign each pixel in the silhouette map to one of thirty-one predefined body parts. To increase saliency, the silhouette map is converted to a depth delta map, where the difference in depth between each pixel and all its neighbors is used as a classification feature. The classification engine is a training forest of decision trees, each trained with over one-million manually labeled ground truth samples. Each decision tree is pruned to a depth of twenty. After each pixel in the silhouette is classified independently by the decision forest, voting classifies each pixel to one of the thirty-one body parts. If the object is determined to be a human user, a skeletal model is then fit to localize the ankles, knees, hips, shoulders, elbows, wrist, head and torso. A local mode-finding approach based on mean shift with a weighted Gaussian kernel is used to determine the skeletal joint positions. The resulting output is a joint 3D skeletal tracking map in real-time.

p-0069Tracked faces from a conventional digital camera providing RGB images are preferably associated with tracked skeletonization from the depth camera. Together, the RGB pixel information and 3D skeletonization joint positions are used by the detect controlling user gesture step <b>360</b>. The 3D locations of the skeletal joints can be used for recognizing gestures associated with moving body parts (e.g., arm motions and hand motions). The pixels from the RGB camera are primarily used to analyze the facial information. As described earlier, the facial information can be useful for the determine controlling user(s) step <b>340</b>. The facial information can also be analyzed to detect certain types of gestures such as head nod gestures or eye movement gestures.

p-0070In accordance with embodiments of the present invention, nonverbal gestures are used in place of, or in addition to, voice commands. The use of nonverbal gestures have an advantage over voice commands in many applications because the detection of verbal commands in crowded or busy environment can be unreliable. If voice commands are used, the usage of multiple microphones can be used to directionalize sounds and speech recognition can be used to segregate one human from another. In the context of the present invention, gestures can include movement of the arms, hands, face or other body parts.

p-0071Any type of gesture that can be performed by a human user can be defined and used in accordance with the present invention. In a preferred embodiment, the predefined set of gestures that are used to control the behavior of the interactive display system <b>200</b> are chosen to be as largely culture agnostic as possible. For example, a single hand wave over the head would be generally recognizable as a gesture for getting someone's attention. This gesture can intuitively be used by a user to get the system's attention. Similarly, a pointing gesture can be used to adjust a pointing location on the digital display <b>205</b> (for example to select an object), and an extended arm with palm facing out can be used to perform a stop command.

p-0072<figref idrefs="DRAWINGS">FIG. 5</figref> illustrates examples of a number of different gestures that can be used to control the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) in accordance with some embodiments of the present invention. These gestures can be easily modified or extended to suit any particular application, culture, or situation, suffice they can be described by the location of 3D joints or facial gestures over time. Application specific and vendor specific gestures are intended to be added above and beyond these basic gestures.

p-0073Pointing gestures <b>500</b> can be used to adjust a pointing location in the information display region <b>245</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). For pointing gesture <b>501</b> the pointing direction of the user's arm (or hand or finger) changes with time. As the pointing direction changes during the pointing gesture <b>501</b> the position of fiducial <b>260</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) is updated to reflect the location in the information display region <b>245</b> where the user is pointing. In some embodiments, the arm pointing direction is determined using the skeleton joint projection method discussed earlier, In some cases, when users wear loose or baggy clothing, or when they are carrying objects or a handbag, the accuracy that the skeleton joints can be determined is affected. As such, it is recommended that selectable objects on the screen be no smaller than 1/20 the width of the screen. For some applications it has been found that full arm extension pointing, rather than forearm pointing (elbow bent) or hand/finger pointing, is both more natural to the human user and also yields more accurate results.

p-0074In an alternate type of pointing gesture <b>502</b>, the pointing direction is determined from the facial orientation or visual focus of attention (i.e., eye gaze) of the user. Empirical studies have shown that head pose gestures are more intuitive when users are in close proximity to the digital display <b>205</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>), while arm pointing gestures are more intuitive for larger distances or larger displays. In some embodiments, both forms of pointing gestures can be supported. However, in applications that require selection and other more advanced gestures, the actor might get confused if she had to go back and forth between head and arm gestures. In that case, it is generally preferable to stick with only arm pointing gestures.

p-0075Because systems are subject to calibration/perspective errors, a fiducial should be placed on the screen, indicating where the human user is looking/pointing. In some embodiments, attributes of the fiducial indicate, the pointing location change depending on the pointing location, a state of the interactive display system <b>200</b>, a characteristic of the controlling user or a gesture made by the controlling user. Examples of attributes of the fiducial that can be changed included the shape, color or size of the fiducial. For example, if the pointing location moves over a selectable active element the form of the fiducial can be changed accordingly (i.e., from a cross-hair symbol for inactive regions of the digital display <b>205</b> to an arrow symbol for an active region corresponding to a clickable button). As discussed earlier, in some applications, the fiducial can be an avatar having characteristics that reflect attributes of the controlling user. In some embodiments, the fiducial can include a tail indicating a history of pointing locations.

p-0076A selecting gesture <b>510</b> can be used to select a selectable active element pointed to by the pointing location (analogous to a mouse click). For the selecting gesture <b>510</b>, the user changes her hand from an open hand pointing position <b>511</b> to a closed first pointing position <b>512</b>, as if you were grabbing an object. An alternate selecting gesture <b>520</b> involves, borrowed from American Sign Language, involves pointing at an object with one hand while bringing the non-pointing hand to the chest, as if you were saying “I want that.”

p-0077Zoom gestures can be used to zoom into or out of the information displayed in the information display region <b>245</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). Zoom gesture <b>530</b> shows an example of a zoom in gesture where the user moves her hands from a hands together position <b>531</b> to a hands apart position <b>532</b>. The user can similarly perform a zoom out gesture by moving her hands from the hands apart position <b>532</b> to the hands together position <b>531</b>. To stop a zoom action at the proper zoom factor, the user simply retracts her arms back to her body when she is satisfied with the zoom level.

p-0078Gestures can be defined to enable the user to stop (or pause) and continue various operations being performed by the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). An example of a stop gesture <b>540</b> involves the user holding out an arm with an open palm. A continue gesture <b>541</b> can be performed by the user rolling of her forearms.

p-0079A relinquish control gesture <b>550</b> can be performed by the user crossing her arms across her chest. When the user performs this gesture, the controlling user is moved to the end of the priority queue and the next user in the priority queue is designated to be the controlling user. To prevent unintentional relinquish control gestures <b>550</b> from irritating the controlling user, a hand raising gesture can be performed immediately after giving the cut gesture will reinstate the user's previous priority value. In some embodiments the relinquish control gesture <b>550</b> can also be used to perform a cut command.

p-0080In some embodiments, a control request gesture can be defined that enables a user that is not the controlling user to request that they be designated as a controlling user. For example, a hand raising gesture (not shown in <figref idrefs="DRAWINGS">FIG. 5</figref>) can be used for this purpose. This type of gesture is intuitively associated with trying to get someone's attention. In some embodiments, the user performing the control request gesture can immediately be designated to be a controlling user. In a preferred embodiment, the relative position of the user in the priority queue is adjusted in response to detection of a control request gesture. One mechanism for implementing this in the context of the priority value calculations described earlier is to add an additional term to the priority value equation:

p-0081<maths id="MATH-US-00003" num="00003"><math overflow="scroll"><mtable><mtr><mtd><mrow><msub><mi>P</mi><mi>i</mi></msub><mo>=</mo><mrow><mrow><msub><mi>W</mi><mi>D</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mrow><mn>1</mn><mo>-</mo><mfrac><msub><mi>D</mi><mi>i</mi></msub><msub><mi>D</mi><mi>m</mi></msub></mfrac></mrow><mo>)</mo></mrow></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>T</mi></msub><mo>⁡</mo><mrow><mo>(</mo><mfrac><msub><mi>T</mi><mi>i</mi></msub><msub><mi>T</mi><mi>m</mi></msub></mfrac><mo>)</mo></mrow></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>C</mi></msub><mo>⁢</mo><msub><mi>C</mi><mi>i</mi></msub></mrow><mo>+</mo><mrow><msub><mi>W</mi><mi>A</mi></msub><mo>⁢</mo><msub><mi>A</mi><mi>i</mi></msub></mrow></mrow></mrow></mtd><mtd><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></mtd></mtr></mtable></math></maths><br /> where A_iis number of attention getting gestures the user has performed, and W_Ais a weighting constant. By default, the A_ivalue would be initialized to zero for each of the detected users. Each time the user performs a control request gesture, the A_ivalue can be incremented by one, thereby increasing the associated priority value and consequently advancing their position in the priority queue. In some implementations, a minimum time interval between successive control request gestures can be defined in order to avoid disruptive behavior by a user.

p-0082In some embodiments, a plurality of different control request gestures can be defined indicating different levels of urgency. For example, a hand waving gesture can be defined which is more urgent than a hand raising gesture. If a hand waving gesture is detected, the A_ivalue can be incremented using a larger increment (e.g., 2).

p-0083If a late-arriving user takes control away from the controlling user, this could be a source of irritation. In some embodiments, a mechanism can be provided to enable the original controlling user to conveniently regain control. For example, if the original controlling user performs a hand raising gesture within a predetermined time interval after being bumped to a lower priority then original controlling user can immediately be restored as the controlling user.

p-0084<figref idrefs="DRAWINGS">FIG. 6</figref> shows an example of a digital display <b>600</b> implementing a digital signage application in accordance with the present invention. The digital display includes a command control region <b>630</b> and an information display region <b>640</b>. The information display region <b>640</b> includes information pertaining to a tourist resort, including photographs, advertisements and various text messages providing useful information and reminders.

p-0085A time sequence of images captured using the digital camera <b>210</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) showing the users located in a field-of-view of digital display <b>600</b> is displayed in the command control region <b>630</b>. Graphical elements (rectangular bounding boxes) are associated with each of the identified users, wherein the color of the graphical elements are used to differentiate the controlling user from the non-controlling users. A text message <b>635</b> is also included in the command control region <b>630</b> which provides a textual indication of the most recent command processed by the interactive display system <b>200</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>). In this case, a “You are driving!” message having the same color as the bounding box for controlling user indicates that a different user has been identified to be the controlling user.

p-0086In this example, the controlling user is currently performing a pointing operation using a head pose pointing gesture. A cross hair fiducial <b>610</b> is overlaid on the digital display <b>600</b>. A fiducial tail <b>620</b> trailing behind the fiducial <b>610</b> provides a visual indication of the path that the fiducial <b>610</b> has traversed. This helps some users focus more quickly on the fiducial mark. In this example, the color of the fiducial tail <b>620</b> fades from a first color (e.g., black) to a second color (e.g., gray) from the start to the end of the tail. In other embodiments, the fiducial tail can fade from opaque to transparent, or can be a constant color. The shape, size, color and transparency of the fiducial <b>610</b> and its fiducial tail <b>620</b> all affect the human user experience.

p-0087Although a cross-hair-shaped fiducial <b>610</b> is quite effective for many applications, fidicials can take any form such as a symbol, a character, a company logo or any graphical element of choice. To help give feedback to the human user, in some embodiments the fiducial <b>610</b> can change color, shape, icon, or be animated to give appropriate feedback during the interaction process responsive to the pointing location or the operation being performed. For example, when a user makes a correct selection, the fiducial <b>610</b> can be changed to a checkmark symbol, or when the interactive display system <b>200</b> is performing a processing operation, the fiducial <b>610</b> can be changed to an hour glass. Similarly, when a user cancels a selection, the fiducial <b>610</b> can change into an “x” symbol. If the user is performing a multistep process, the fiducial can incrementally change at each step. If a display allows multi-user interaction, each controlling user should have their own fiducial having a unique appearance that is somehow associated with the user (e.g., having a unique color or shape). In some embodiments, it may be desirable to enable each user to select their own personal fiducial marker, or design a personal avatar responsive to detected characteristics of the user.

p-0088The controlling user can interact with the content on the digital display <b>600</b> in various ways. For example, a selecting gesture <b>510</b> can be used to select a displayed object. If the selected object is a selectable active element, then an associated predefined action is performed. In other cases, the selected object can be manipulated in various ways after it is selected. In some embodiments, a selected object can be unselected by performing a second selecting gesture <b>510</b> to toggle the object selection. If a selected object is a draggable item, it can be moved around on the display using movement gestures. For example, movement gestures are defined where the user point an arm toward the object (or straight towards the digital display <b>600</b>), then moves the arm in the direction that the user wants to move the object. Zoom gestures <b>530</b> can also be used zoom into or out of the selected item. Other gestures such as stop gestures <b>540</b>, continue gestures <b>541</b> or relinquish control gestures <b>550</b> can also be used to interact with the system.

p-0089In some embodiments, facial pose tracking is used so that the system can know and understand what the user is looking at. In addition to using the facial pose information for various gestures as discussed earlier, it can also be used for other purposes. For example, if it is determined that the controlling user has not been looking at the display for a prolonged period of time, the system can skip to the next user in the priority queue (or the display can be reset when the system is operating in a single user mode).

p-0090In some embodiments, facial expression can be used to gauge the emotion of the actor. Neutral or happy emotions are indicative of user agreement or satisfaction. Surprise is indicative of amusement. Sad is a warning that content may not be appropriate. Depending on the application, angry emotions will have a different affect. For example, in a window shopping application, the detection of anger would trigger a change of content—perhaps a different style or color of clothing. However, in an airport terminal, airplane arrival status screens should generally be anger agnostic. As computer vision algorithms and hardware improve, it will one day be able to reliably read lips of the controlling user, making it possible to accept spoken commands even in noisy environments.

p-0091Facial identity can be used to both verify tracking over time, as well as remember user history and preferences. Should the same user return back to the same interactive display system, the interactive display system can recognize the user and act accordingly. For example, if an interactive display system is positioned at the entrance to a workplace, it can be used to greet users by name and provided customized informational messages as they enter work. In this case, the interactive display system can also be used to verify the user's identity, thereby acting as a security device. Similarly, digital ATMs and interactive gambling systems may use facial identity as a primary or secondary security feature. In some applications, user preferences might include a user's zip code for a weather oriented digital sign, previous purchases for a store front, or flight seat assignment preferences in an airport.

p-0092User attributes such as age, gender, and race can be collected for each user that interacts with the sign. As such, demographics can be collected for later targeted marketing. For example, a digital sign in front of a department store may have thousands of people interact with it each day. By interacting with users, the sign may offer various advertisements and provide easy ways for consumers to shop and compare or check inventory in the store. As part of the user interactions, coupon codes or other incentives to enter the store may be displayed. Statistics can be collected regarding how often particular types of displayed advertising content cause users in various demographic categories to enter the store. For example, it may be determined that middle aged Hispanic woman respond favorably to the new line of Gucci hand bags, and teenage African American boys have no interest in the new line of Levi's shirt-ware. Based on the collected data, data processing systems (e.g., “recommender systems”), such as those used as the underlying intelligence for shopping sites such as amazon.com or shared services such as Netflix movie section, are used for predicting user preferences. As new users are detected, people with similar interests or attributes are statistically coupled for an improved interaction experience. Further, an interest level database can be formed and updated providing an indication of the advertising effectiveness (e.g., as characterized by a determined user interest level) as a function of one or more demographic attributes. In some embodiments, the interest level database can be formed off-line and can be loaded into a storage memory in the interactive display system <b>200</b>.

p-0093The advertising content displayed on the system can now be geared toward the demographics of users interacting with the system responsive to the interest level database and determined demographic attributes for the users (e.g., newly arriving Hispanic woman will be preferentially shown advertisements pertaining to the new line of Gucci bags). The controlling user can then interact with the displayed advertisement using appropriate gestures. For example, the controlling user can use a pointing gesture and a selection gesture to select a product in the displayed advertisement. Additional information pertaining to the selected product can then be provided, such information about available colors/sizes, and sale prices.

p-0094The content displayed by the system can also be tailored in other ways according to user demographics. For example, age attributes of the users can be used to control various system attributes such as the form of the fiducials, where children get cartoon-based fiducials, while adults get fiducials formed using company logos. Similarly, males and females would see gender appropriate apparel displayed.

p-0095Multiple display systems <b>200</b> in similar or dissimilar locales can be networked with one another for enhanced experiences. In this case, the display systems <b>200</b> will include some type of network interface such as a WiFi interface or an Ethernet interface. For example, the identity of users can be shared amongst multiple devices located in a mall, so a user who interacts with one display on the way in and another during her shopping visit is recognized by the second display. Similarly, demographic statistics can be shared across multiple systems making for more robust and pleasing recommender systems and targeted marketing scenarios in shorter durations of time. By networking multiple displays together, it is also possible for two or more users at different locales to link up with one another, sharing a similar application for informational sharing, personal entertainment, gaming, or multi-way video conversations.

p-0096The operation of prior art interactive digital signage applications can often be confusing in multi-user situations due to uncertainty about which user the system is responding to. In accordance with the present invention, the information displayed in the command control region <b>630</b>, along with a few simple rules and gestures, solve these problems.

p-0097In order to enable natural two-way communication, it is important for users would like to know what the system is “thinking” The command control region <b>630</b> includes a live video stream of what the digital camera <b>210</b> (<figref idrefs="DRAWINGS">FIG. 2</figref>) is seeing. While <figref idrefs="DRAWINGS">FIG. 6</figref> shows the command control region <b>630</b> positioned in the lower-right corner of the digital display <b>600</b>, in various embodiments it can be placed anywhere where it minimally disrupts the signage content, but it should generally be positioned in an obvious location that is visible from all user viewpoints. The content displayed in the command control region <b>630</b> informs the user what the computer is seeing, answering common questions such as “Am I in the camera field of view?”, “Is my head getting cut off?”, “Does the computer recognize me?”, and so on.

p-0098In <figref idrefs="DRAWINGS">FIG. 6</figref>, four human users are standing in front of the digital display <b>600</b>. The command control region <b>630</b>, shows those four users, providing a clear indication that the system sees all four users. The command control region <b>630</b> also includes graphical elements, (rectangular face boxes) associated with each of the users, confirming that all four users are being tracked by the system. The coloration of the graphical elements communicates to the users who the system is recognizing to be the controlling user. For example, the user that is currently in control of the system can be shown with a green rectangular face box, while the user that is next in priority queue can be shown with a yellow face box. The graphical elements for the rest of the users will gradually go from yellow to red, providing an indication of their relative position within the priority queue.

p-0099In some embodiments, to make the command control region <b>630</b> more informative, the detected head pose and facial expression can be reported back to the user via animated avatars. For example, the avatar faces can mimic the facial expressions, as well as the facial pose (pitch, roll, yaw) for the corresponding users. Each face can be replaced with an avatar, or small avatars can be placed next to each face. For example, “smiley face” avatars can be displayed next to each face box, where the actual expression and pose of the smiley face mimics that of the human user. In some applications, the avatars can be custom designed for a particular theme associated with the content or provider of the interactive display system (e.g., Mickey Mouse, Pillsbury Dough Boy, Harry Potter, or the Microsoft Paper Clip).

p-0100A computer program product can include one or more non-transitory, tangible, computer readable storage medium, for example; magnetic storage media such as magnetic disk (such as a floppy disk) or magnetic tape; optical storage media such as optical disk, optical tape, or machine readable bar code; solid-state electronic storage devices such as random access memory (RAM), or read-only memory (ROM); or any other physical device or media employed to store a computer program having instructions for controlling one or more computers to practice the method according to the present invention.

p-0101The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

p-0102<tables id="TABLE-US-00001" num="00001"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><thead><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row><row><entry>PARTS LIST</entry></row><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="1" colwidth="63pt" align="char" char="." /><colspec colname="2" colwidth="154pt" align="left" /><tbody valign="top"><row><entry>110</entry><entry>data processing system</entry></row><row><entry>120</entry><entry>peripheral system</entry></row><row><entry>130</entry><entry>user interface system</entry></row><row><entry>140</entry><entry>data storage system</entry></row><row><entry>200</entry><entry>interactive display system</entry></row><row><entry>205</entry><entry>digital display</entry></row><row><entry>210</entry><entry>digital camera</entry></row><row><entry>220</entry><entry>field of view</entry></row><row><entry>231</entry><entry>user</entry></row><row><entry>232</entry><entry>user</entry></row><row><entry>240</entry><entry>command control region</entry></row><row><entry>245</entry><entry>information display region</entry></row><row><entry>250</entry><entry>image</entry></row><row><entry>251</entry><entry>user image</entry></row><row><entry>252</entry><entry>user image</entry></row><row><entry>260</entry><entry>fiducial</entry></row><row><entry>261</entry><entry>controlling user graphical element</entry></row><row><entry>262</entry><entry>secondary user graphical element</entry></row><row><entry>310</entry><entry>display images in command control region step</entry></row><row><entry>320</entry><entry>user detection/tracking step</entry></row><row><entry>330</entry><entry>users found test</entry></row><row><entry>340</entry><entry>determine controlling user(s) step</entry></row><row><entry>350</entry><entry>update command control region step</entry></row><row><entry>360</entry><entry>detect controlling user gesture step</entry></row><row><entry>370</entry><entry>gesture detected test</entry></row><row><entry>380</entry><entry>update information display region step</entry></row><row><entry>390</entry><entry>update command control region step</entry></row><row><entry>400</entry><entry>depth image</entry></row><row><entry>410</entry><entry>user</entry></row><row><entry>411</entry><entry>user</entry></row><row><entry>500</entry><entry>pointing gestures</entry></row><row><entry>501</entry><entry>pointing gesture</entry></row><row><entry>502</entry><entry>pointing gesture</entry></row><row><entry>510</entry><entry>selecting gesture</entry></row><row><entry>511</entry><entry>open hand pointing position</entry></row><row><entry>512</entry><entry>closed fist pointing position</entry></row><row><entry>520</entry><entry>selecting gesture</entry></row><row><entry>530</entry><entry>zoom gesture</entry></row><row><entry>531</entry><entry>hands together position</entry></row><row><entry>532</entry><entry>hands apart position</entry></row><row><entry>540</entry><entry>stop gesture</entry></row><row><entry>541</entry><entry>continue gesture</entry></row><row><entry>550</entry><entry>relinquish control gesture</entry></row><row><entry>600</entry><entry>digital display</entry></row><row><entry>610</entry><entry>fiducial</entry></row><row><entry>620</entry><entry>fiducial tail</entry></row><row><entry>630</entry><entry>command control region</entry></row><row><entry>635</entry><entry>text message</entry></row><row><entry>640</entry><entry>information display region</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>